DRAFT UGANDA STANDARD  
 
  DUS 203  
Fourth  Edition  
2010 -10-19 
 
 Reference number  
DUS 203:2010  
© UNBS 2010   
  
Food grade salt — Specification  
 DUS 203:2010  
ii © UNBS  2010  – All rights reserved  
 Compliance with this standard does not, of itself , confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct applica tion 
© UNBS  2010 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and microfilm, without prior written 
permission from U NBS.  
Requests for permission to reproduce this document should be addressed to  
The Executive Director  
Uganda National Bureau of Standards  
P.O. Box 6329  
Kampala  
Uganda  
Tel: 256 41 4 505 995  
Fax: 256 41 4 286 123  
E-mail: unbs@infocom.co.ug  DUS 203:2010  
© UNBS 2010  – All rights reserved  iii 
 Table of Contents  
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  2 
4 Requirements  ................................ ................................ ................................ ................................ .........  3 
4.1 Types of food grade salt  ................................ ................................ ................................ .......................  3 
4.2 General requirements  ................................ ................................ ................................ ...........................  3 
4.3 Particle size  ................................ ................................ ................................ ................................ ............  4 
4.4 Moisture content  ................................ ................................ ................................ ................................ .... 4 
4.5 Chemical characteristics  ................................ ................................ ................................ ......................  4 
4.7 Use as  a carrier  ................................ ................................ ................................ ................................ ...... 5 
5 Food additives and processing aids  ................................ ................................ ................................ ... 5 
5.1 Food additives  ................................ ................................ ................................ ................................ ....... 5 
5.2 Processing aids  ................................ ................................ ................................ ................................ ..... 5 
6 Contaminants  ................................ ................................ ................................ ................................ .........  5 
7 Hygiene  ................................ ................................ ................................ ................................ ...................  6 
8 Packaging  ................................ ................................ ................................ ................................ ...............  6 
9 Labelling  ................................ ................................ ................................ ................................ .................  6 
10 Methods of test  ................................ ................................ ................................ ................................ ...... 7 
11 Methods of sampl ing ................................ ................................ ................................ .............................  7 
Annex A (normative) Test for visible impurities ................................ ................................ ..............................  8 
Annex B (normative)  Determination of the chloride content, calculated a s sodium chloride  ..................  9 
Annex C (normative)  Methods for determination of iodine in food grade salt  ................................ .........  11 
Annex D (normative)  Methods of sampling food grade salt  ................................ ................................ ....... 13 
Annex E (normative)   Microbiological test for the presence of red halophylic bacteria  ..........................  15 DUS 203:2010  
iv © UNBS  2010  – All rights reserved  
 Foreword  
Uganda National Bureau of Stand ards (UNBS) is a parastatal under the Ministry of Tourism, Trade and 
Industry established, under Cap 327 of the Laws of Uganda.  UNBS is mandated to co -ordinate the 
elaboration of standards and is  
(a) a member of International Organisation for Standardisation  (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT/SPS Agreements of the World Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out through Technica l Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of representatives of 
consumers, traders, academicians, manufacturers, government and other stakeholders.  
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council . 
The Uganda standards US 203 on edible sa lts was first published in 1994. It was revised in 1999 and 2006. 
This draft standard DUS 203:2010 will form the fourth edition following revision to prescribe levels for 
iodisation at production and border entry p oints in Uganda and lower the maximum amount of iodine to be 
added to the salt.  
This fourth editio n will cancel s and replace s the third edition, US 203:2006 , which has been technically 
revised.  
This Uganda Standard US 203 :2010 ; Food grade salt  — Specificat ion, was prepared by the Sub Committee o n 
Nutrition and Foods for Special Dietary Uses under the Food and Agriculture Standards Technical Committee 
(TC 2 ). The efforts of the committee members and all other stakeholders are acknowledged.  
 UGANDA STANDARD  DUS 203:2010  
 
ICS 71.060.50  
Price based on 24 pages  
© UNBS 2010 – All rights reserved   
 Food grade salt  — Specification  
1 Scope  
This Draft Uganda S tandard specifies the requirements and methods of sampling and test for food grade salts 
obtained from the sea, from underground rock salt deposits and from natural brine intended for human 
consumption either thro ugh direct sale to the consumer or use in food manufacturing.  It also applies to salt 
used as a carrier of food additives or nutrients (or both).  
This standard does not apply to salt which is a by product of chemical industries.  
2 Normative references  
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
US 7, General standard for the labelling of pre -packaged foods  
US 28, Code of hygiene practice for the food and drink manufacturing industry  
US 45, General standard for food additives  
US 500, General requirements for nutrition labelling of foods  
US 508, General requirements for nutrition an d health claims on foods  
US 566, Use of nutrition claims — Requirements  
DUS ISO 2479 , Sodium chloride — Determination of matter insoluble in water or in acid and preparation of 
principal solutions for other determinations  
DUS ISO 2480 , Sodium chloride  for industrial use  — Determination of sulphate content — Barium sulphate 
gravimetric method  
DUS ISO 2481 , Sodium chloride — Determination of halogens, expressed as chlorine — Mercurimetric 
method  
DUS ISO 2482 , Sodium chloride — Determination of calcium and magnesium contents — EDTA 
complexometric methods  
DUS ISO 2483 , Sodium chloride — Determination of moisture content (loss of mass at 110 °C)  
2 © UNBS  2010  – All rights reserved  
 US 110,  Sodium chloride  for industrial use  — Determination  of cadmium content  
US 112, Sodium chloride — Determination of lead content  
US 113, Sodium chloride — Determination of mercury content  
US 114,  Sodium chloride — Determination of pH and total alkalinity  
US 116, Sodium chloride — Determination of anti -caking additives content  of salt  
SI No. 2. 2005 The Food a nd Drugs (Food Fortification) Regulations; 2005.  
3 Terms and definitions  
For the purpose of this standard, the following terms and definitions shall apply.  
3.1 
food grade salt  
is a crystalline product consisting predominantly of sodiu m chloride which is used as an ingredient or 
flavourant in or on foodstuff, and which may be obtained from the sea, underground rock salt deposits or 
natural brine, and which may also be referred to as table salt, cooking salt, or common salt;.  
3.2  
commer cial grade salt  
general purpose salt suitable for human consumption and food manufacturing and which complies with the 
minimum requirements of the Codex standard for food grade salt (see CODEX STAN 150)  
 
3.3 
technical grade salt  
premium grade salt that mee ts the technical requirements for higher purity than commercial grade salt and 
which is used as table salt and in specialized food manufacturing processes  
 
3.4 
household salt  
cooking salt  
common salt;.  
food grade salt intended for use in household for cook ing  
3.5 
table salt  
salt that is a predominately white crystalline sodium chloride product suitably coated with free flowing agents 
such as light magnesium carbonate, calcium carbonate, tri -calcium phosphate or calcium silicate, so as to 
retard moisture ab sorption, caking and to impart the free flowing property to the salt  
3.6 
food manufacturing salt  
salt that is designated for manufacturing of food products  
3.7 
food additive  
any substance not normally consumed as a food by itself and not normally used as a  typical ingredient of the 
food, whether or not it has nutritive value, the intentional addition of which to food for a technological 
(including organoleptic) purpose in the manufacture, processing, preparation, treatment, packing, packaging, 
transport or holding of such food results, or may be reasonably expected to result, (directly or indirectly) in it or  
© UNBS 2010  – All rights reserved  3 
 its by -products becoming a component of or otherwise affecting the characteristics of such foods. The term 
does not include “contaminants” or substance s added to food for maintaining or improving nutritional qualities.  
3.8 
anti-caking agent  
agent added to improve the free running qualities of salt  
3.9  
iodised salt  
food grade salt, which is used as a carrier of iodine for public health reasons. The comm only used iodising 
agents include potassium iodate and potassium iodide.  
3.10 
fortified salt  
food grade  salt, which is used as a carrier of micronutrients for public health reasons.  
3.11 
sterilised salt  
salt that has been treated to ensure a product free f rom red halophylic bacteria  
 
4 Requirements  
4.1 Types of food grade salt 
Food grade salt  shall be presented in one of the following types:  
Commercial grade salt, which may be further divided into the following subtypes:  
a) Household  salt, common salt  or co oking salt  
b) Sterilized  salt 
Technical grade salt, which may be further divided into the following subtypes:  
a) Table  salt 
b) Food  manufacturing salt  
4.2 General requirements  
4.2.1 Colour  
Food grade salt shall be white in colour, and a solution that conta ins 10 g of salt in 100 mL distilled water shall 
be clear and colourless.  
4.2.2 Visible impurities  
Food grade salt  shall be practically free from grit and other extraneous adulterants  when the sample is tested 
in accordance with Annex A.   
4 © UNBS  2010  – All rights reserved  
 4.3 Particle size  
For t able salt, 99 % of the material shall pass through a 1.00 mm (1 000 micron) sieve and not more than 20 
% by mass of the material shall pass through a 0.212 mm or a 212 -micron sieve . 
Unless agreed to between the supplier and the purchaser, salt for foo d manufacture shall be such that 100% 
of the material shall pass through a 212 -micron sieve;  
For all other types, the fineness of grain of salt may be agreed upon by  the supplier and purchaser . 
4.4 Moisture content  
When determined in accordance with DUS IS O 2483 , the moisture content of food grade salt shall be not 
greater than 0.5 % by mass.  
4.5 Chemical characteristics  
When tested in accordance with methods as indicated, food grade  salt, shall conform to the requirements in 
Table 1.  
Table 1 — Requirements  for food grade salt 
Characteristics  Requirements  Method of Test  
Chloride content as (NaCl), on dry matter 
basis, % m/m, min  97.0 Annex B  
Matter insoluble in water, on dry matter 
basis, % m/m, max  0.2 US 103  
Calcium ( as Ca) water soluble, on dry matter 
basis,% m/m, max  0.10 US 107  
Copper, (as Cu),  on dry matter basis,  mg/kg, 
Max 2.0 US 111  
Magnesium (Mg) water -soluble, on dry matter 
basis, % m/m, max  0.10 US 107  
Sulphate (as SO 4), on dry matter basis, % m/m, 
max 0.50 US 105  
Total alkalinity (Na 2CO 3), on dry matter 
basis, % m/m, max  0.20 US 114  
pH range  7.0 - 8.0 US 114  
Acid insoluble matter , on dry matter basis,  % 
m/m, max  0.2 US 103  
 
4.6 Iodisation of food grade salt  
Food grade salt shall be iodised with food grade sodium or potassium iodate or iodi de in such a manner that 
the salt shall  conform to the requirements in Table 2.   
© UNBS 2010  – All rights reserved  5 
 Table 2 — Requirements for iodine in food grade salt, mg per kg at p oint of manufacture, point of 
entry for imported salt and point of retail  in Uganda  
Point of control  Minimu m, 
mg/100g   Maximum,  
mg/100g   Method of test  
Requirement at point of manufacture 
in Uganda or Point of entry for 
imported salt  3 5 
Annex C 
Point of retail shop or market   2.5 5 
Note: When iodide is used for iodisation care should be taken to ensure th at the iodide compound is stabilised or that an overage in the addition 
of the compound to use to ensure the levels of iodine are maintained.  
 
4.7 Use as a carrier  
When used as a carrier for food additives such as mixtures of nitrate and/or nitrite (curing  salt) or nutrients 
such as fluoride, iodine, iron, and vitamins the salt shall be of food grade quality.  
5 Food additives  and processing aids  
5.1 Food additives  
Food additives may be used in the manufacture of food grade  salt in accordance with US 45.  
5.2 Processing aids  
Dimethylpolysiloxane shall have a maximum level of 10 mg of residue/kg in the product.  
6 Contaminants  
Food grade salt shall not contain contaminants in amounts and in such form that may be harmful to the health 
of the consumer. In particu lar the limits in Table 3 shall not be exceeded.  
Table 3 — Limits for contaminants  
Contaminants  Maximum 
limit, (mg/kg)  Method of Test  
Arsenic (as As)  0.5 DUS-1 
Lead (as Pb)  2.0 US 112  
Cadmium (as Cd)  0.5 US 110  
Mercury (Hg)  0.1 US 113  
                                                      
1 Adopt: ESPA/CN -E/105, Sodium chloride – Determination of arsenic – Silver diethyldithiocarbamate  
photometric method 1).   
6 © UNBS  2010  – All rights reserved  
 7 Hygiene  
In ord er to ensure that proper standards of food hygiene are maintained until the product reaches the 
consumer food grade salt shall be handled in accordance with US 28.  
When tested in accordance with 5.9, sterilised food grade salt shall be free from red haloph ylic bacteria.  
8 Packaging  
Food grade salt shall be p ackag ed in air tight bags of either high density polyethylene (HDPE ) or 
polypropylene ((PP) (laminated or non laminated) ) or   jute bags or sisal bags with Low density polyethylene 
(LDP) liner or nylon b ags or multi -layer paper bags whichever  is applicable and any other suitable food grade 
material.  
Bulk packaging sh all not exceed 50 kg  
Small quantities shall be packed in HDPE/LDPE  or polypropylene  and/or paper bags.  
The material used to package food gra de salt shall be clean, to protect it from contamination and shall not 
react with the salt.  
Types of bags which are normally used for packaging commodities such as fertilizers or chemicals and bags 
that have been used for such purposes shall not be reused for packaging of iodised  salt. 
9 Labelling  
9.1 Food grade salt shall be clearly labelled with true and accurate information and in a manner 
conforming to US 7 , US 500, US 508 and US 566 and shall show the following: - 
(a) Name of product  
(i) The name of the product  as declared on the label shall be “iodised salt”. 
(ii) The type of the salt shall be declared on the label in close proximity to the name salt as either 
“Food Grade Salt” Or “Common salt”, “Cooking Salt”, “Household Salt” or “Table Salt”.  
(iii) The term "dendritic S alt" may only be used when one or more ferrocyanide salts have been added 
to the salt during the crystallization step in the production.  
(iv) Where salt is used as a carrier for one or more nutrients, the name of the product shall be 
indicated on the label for example , "Iodised salt", “Salt fortified with vitamins"  and “Salt Fortified 
with Iron”  
(b) the name and physical address of the manufacturer, importer or distributor;  
(c) the list of ingredients indicating the compound used to iodise the salt;  
(d) the date of manufact ure; 
(e) the country of manufacture;  
(f) the lot or batch identification number;  
(g) the net weight of the salt;   
© UNBS 2010  – All rights reserved  7 
 (h) the expiry date;  
(i) the level of iodine in mg/100g; and  
(j) the caution label indicating that the salt must be stored in a cool and dry place.  
9.2 The food forti fication logo may be displayed on the label of salt provided that it is done in accordance with 
the food fortification regulations  
9.3 Salt intended for industrial purposes shall not be offered for sale for human consumption and shall not be 
labelled as fo od grade or common salt.  
10 Methods of test  
Testing of food grade salt shall be carried out using the methods declared in the appropriate clause of this 
standard.  
11 Methods of sampling  
Sampling of food grade salt shall be carried out in accordance with An nex D   
8 © UNBS  2010  – All rights reserved  
 Annex A 
(normative)  
Test for visible impurities  
Dissolve 50 g of the salt in approximately 500 mL distilled water and filter the solution through a flock  pad. 
Examine the pad for visible impurities.  
 
  
© UNBS 2010  – All rights reserved  9 
 Annex  B 
(normative)  
 
Determination of the chlorid e content, calculated as sodium chloride  
1 Apparatus  
Normally available laboratory glassware.  
2 Reagents  
2.1 Potassium chromate solution . 
Dissolve 5 g of potassium chromate (K 2CrO 4) in 100 mL of water.  
2.2 Standard 0,1 N silver nitrate solution  
2.2.1  Prepa ration  
Dissolve 17,0 g of silver nitrate (AgNO 3) in 1 000 mL of water. Store the solution in the dark.  
2.2.2  Standardization  
Carry out the standardization in triplicate.  
Weigh out accurately 5,8 g of analytical reagent grade sodium chloride (NaCl) (previou sly dried at  
200 °C ± 50 °C for 2 h and cooled to room temperature in a desiccator) into a 1 L volumetric flask and  
dissolve it in approximately 200 mL of water. Adjust the temperature of this solution to 20 °C and dilute it  
to 1 000 mL with water at the s ame temperature. Pipette 25 mL of the sodium chloride solution at 20 °C  
into a 250 mL conical flask, add 1 mL of potassium chromate solution, and titrate with the 0,1 N silver  
nitrate solution until a faint reddish -brown colour persists after brisk shaking . Carry out a blank titration  
using the same procedure but replacing the 25 mL sodium chloride solution with 25 mL water.  
 
Calculate the mean normality of the silver nitrate solution from the triplicate determinations.  
N = 
  
where  
N is the norm ality of silver nitrate solution;  
A is the mass of sodium chloride, in grams, in 1 000 mL solution;   
10 © UNBS  2010  – All rights reserved  
 b is the volume of silver nitrate solution, in millilitres, required to titrate 25 mL of sodium chloride  
solution;  
c is the volume of silver nitrate solutio n, in millilitres, required to titrate the blank.  
NOTE A commercially prepared volumetric solution may be used instead.  
3 Procedure  
Carry out the determination in triplicate on each of the test samples.  
Pipette 50 mL of the principal solution reserved in 5 .7.3 at 20 °C, into a 250 mL volumetric flask and dilute to 
250 mL with water at the same temperature. Mix well and pipette 25 mL of this solution at 20 °C into a 250 mL 
conical flask. If the solution is acid to litmus, neutralize with sodium bicarbonate s olution; if the solution is 
alkaline, add dilute nitric acid (1:10) drop by drop until the solution is acid to litmus and then neutralize with 
sodium bicarbonate solution. Add 1 mL of potassium chromate solution and titrate with the standard 0,1 N 
silver n itrate solution until a faint reddish -brown colour persists after brisk shaking.  
4 Calculation  
Calculate the chloride content as NaCl, on a moisture -free basis (and free -flowing agent -free 
basis, where relevant), as a percentage, as follows:  
 
 
 
 
where  
C is the chloride content, as NaCl, expressed as a percentage (by mass);  
a is the volume of silver nitrate solution, in millilitres, used in the titration;  
N is the normality of the silver nitrate solution;  
B is the mass of sample, in grams, in 1 000 mL princ ipal solution, corrected for moisture content  
and, where relevant, the drier content.  
 
5 Report  
Report the chloride content of each test sample as the mean of its triplicate determinations.   
© UNBS 2010  – All rights reserved  11 
 Annex C  
(normative)  
 
Methods for determination of iodine in food grade salt  
C.1 Reagents  
C.1.1  Standard sodium thiosulphate  (Na 2S2O3), 0.005 M. Dissolve 1.240 g AR grade Na 2S2O3 in 
previously boiled distilled water and make up to 1 L.  
C.1.2  Sulphuric acid  (H2SO 4), 1 M  
C.1.3  Potassium iodide  (KI) AR grade, 10 % solution.  Dissolve 10 g of KI in 100 mL of distilled water.  
C.1.4  Starch solution, 1 %. Dissolve 1 g of soluble starch in 10 mL of boiling distilled water. To this add 90 
ml of saturated NaCl solution.  
C.1.5  Bromine water , saturated aqueous solution. Determine the approximate concentration (mg/L) by 
adding from the burette a measured volume to a flask containing 5 mL of 10 % KI solution and 5 mL of dilute 
H2SO 4 and titrate the liberated iodine with 0.1 N sodium thiosulphate solution.  
1 mL of 0.1 N Na 2S2O3 = 8 mg of  bromine = 12.7 mg of iodine  
C.1.6  Sodium sulphite,  1 % (m/v)  
C.1.7  Methyl orange — Dissolve 0.01 g methyl orange in water and dilute to 100 mL.  
C.1.8  Phenol solution,  5 % (m/v)  
C.2 Preparation of the sample solution  
Dissolve 50 g of given salt in distil led water. Transfer to 250 mL volumetric flask and fill to the mark. Measure 
50 mL of this solution for the test in A.3.  
C.3 Procedure  
C.3.1  Method A : When iodide is used to iodise salt  
C.3.1.1  Measure 50 mL of the test solution (10 g NaCl content) and tra nsfer to 200 mL Erlenmeyer flask. 
Neutralize with 1 M sulphuric acid, using methyl orange as an indicator. Add bromine water drop -wise from a 
burette in a quantity equivalent to 10 mg of bromine. Allow standing for a few minutes. Add 1 % sodium 
sulphite by  drops while mixing to destroy a greater portion of bromine. Wash down the neck and sides of the 
flask with water and complete the destruction of bromine by adding 1 or 2 drops of 5 % phenol.  
C.3.1.2  Add 1 mL of 1 M H 2SO 4 and 5 mL of 10 % potassium iodide  solution. Titrate the liberated iodine 
with 0.005 M sodium thiosulphate adding starch as an indicator towards the end of the titration. Carry out a 
blank determination of the reagents and make one or more control determinations using 100 mL of sodium 
chloride solution to which has been added an appropriate quantity of potassium iodide control solution.   
12 © UNBS  2010  – All rights reserved  
 C.3.1.3  For the calculation of the iodine, the following equation is used:  
 

MNV V 2 1 28755mg/kg(I), Iodine.  
where,  
V1 is the volume, in mL, of standard thiosulphate  solution required for the test with the prepared sample 
solution;  
V2 is the volume, in mL, of standard thiosulphate solution required for the blank determination;  
N is the normality of standard thiosulphate solution; and  
M is the mass, in g, of the materi al taken for the test.  
C.3.2  Method B (Alternate method when iodate is used for iodising salt)  
C.3.2.1  Measure 50 mL of the prepared sample solution (A.2). Add 1 mL of 1 M sulphuric acid and 5 mL 
of 10 % potassium iodide. Keep in the dark for 10 min. Titra te the liberated iodine with 0.005 M sodium 
thiosulphate using starch as an indicator.   
C.3.2.2  For the calculation of the iodine, the following equation is used:  
Iodine (I), mg/kg = 5.2875 x V1 
where  
V1 is the volume, in mL, of sodium thiosulphate soluti on required for the test with the prepared sample 
solution.  
C.3.3  Expression of Iodine (I), mg/kg on dry weight basis  
Mkgmg Iodine 100100mg/kg,I Iodine / ,
 
where  
Iodine mg/Kg is the iodine content determined as in A.3.1.3 and A.3.2.1 and  
M is the percent moisture cont ent of sample.  
  
© UNBS 2010  – All rights reserved  13 
 Annex D  
(normative)  
 
Methods of sampling food grade salt  
D.1 Definition  
lot 
collection of packages of the same size, type and style which have been manufactured and packaged under 
essentially the same conditions. If the consignment is decla red to consist of different batches, the batches 
shall be marked separately and the group of containers in each batch shall constitute separate lots.  
D.2 General requirements of sampling  
In drawing, stirring, preparing and handling test samples, the precau tions below shall be observed.  
a) Samples shall not be taken at a place exposed to weather.  
b) Precautions shall be taken to protect the samples, the sampling instrument and the containers for 
samples from adventitious contamination.  
c) To draw a representative sam ple, the contents of each container selected for sampling shall be mixed 
thoroughly by suitable means.  
d) The sample shall be placed in clean, dry and airtight glass or plastic containers that are suitable.  
e) Each sample container shall be sealed airtight after  filling and marked with full details of sampling, the 
date of sampling and year of manufacture.  
f) The number of packages (n) to be selected from a lot shall depend upon the size of the lot (N) and 
shall be in accordance with Table 1.  
Table 1 — Number of pa ckages to be selected for sample  
Lot size  
(N) Number of packages to be selected  
(n) 
5 to 100  
101 to 500  
501 to 1000  
1001 to above  4 
5 
7 
10 
NOTE: When the size of the lot is four or less the number of packages to be 
selected should be as agreed to between  the purchaser and the supplier.  
 
g) The packages shall be selected at random, using tables of random numbers. If these are not available, 
the following procedure shall be applied: Starting from any package, count all the packages in order as 1, 
2, 3 ....  N, selecting every kth  package, where k is the integral part of N  n.  
14 © UNBS  2010  – All rights reserved  
 h) The minimum size of sample to be taken during sampling shall be as follows:  
 for salt in bulk or pre -packaged in more than 1 kg packages, 250 g of salt shall be taken as per 
Table 1 ; and  
 for salt pre -packaged in 500 g or 1 kg packages, one package of salt shall be taken as per Table 
1. 
D.3 Preparation of test samples  
The contents of the packages selected as per B.2 shall be thoroughly mixed, and by a process of quartering, 
the sample  shall be reduced to about 500 g for testing.  
The test sample shall be immediately transferred to a sample container for testing purpose.   
© UNBS 2010  – All rights reserved  15 
 Annex E  
 
Microbiological test for the presence of red halophylic bacteria  
(normative)  
 
E1  Apparatus  
E1.1  Medicine fl ats, two.  
E1.2 Autoclave, at 121 °C ± 1 °C.  
E1.3 Metal container , with a suitable lid.  
E1.4 Waring blender, sterile.  
E1.5 Petri dishes , sterile, with a diameter of 95 mm.  
E1.6 Incubator, at 37 °C ± 1 °C.  
E.2  Reagents  
E2.1 Sodium chloride, analytical reage nt grade.  
E2.2 Skim milk salt agar (SMS).  
E2.3 Bacto -agar.  
E3  Preparation  
Dissolve 5 g of magnesium sulfate (MgSO 4·7H 2O), 1 g of magnesium nitrate (Mg(NO 3)2·6H 2O), 0,25 g of ferric 
chloride (FeCl 3·6H 2O), 10 g of glycerol, 5 g of proteose peptone and 200 g  of sodium chloride in 1 000 mL 
water (heat if necessary). Adjust the pH of the solution to a value between 7,2 and 7,5.  
Transfer the prepared brine to two medicine flats, 500 mL to each. Sterilize both portions at 121 °C ± 1 °C for 
15 min in an autoclave and store until the SMS plates are prepared. When the plates are required, pour one 
500 mL portion of the nutrient brine into a 1,5 L flask and place in a water bath at ± 60 °C. Add 15 g of Bacto -
agar to the other 500 mL portion and autoclave at 121 °C ± 1  °C for 15 min to dissolve the agar. Transfer the 
flask containing the nutrient brine and agar to the water bath. When the first portion of 500 mL nutrient brine 
(not containing any agar) has reached ± 60 °C, pour into a sterile Waring blender, add 50 g of  skim milk 
powder and mix well. Place this mixture back into the water bath, heat to ± 60 °C, and then add it slowly to the 
agar mixture. Check the pH and adjust to a value between 7,2 and 7,5, if necessary. Pour 20 mL portions of 
this final mixture into p etri dishes.  
Allow to set, and store the SMS plates in a refrigerator at 3 °C ± 2 °C until needed.  
E.4  Procedure  
Thoroughly mix the salt sample by using a sterile spatula. Sprinkle 1 g of salt over the surface of a SMS plate. 
Close the petri dish lid with out delay and allow to stand for a few minutes before inverting the plate. Set up two 
plates per sample in this way. Place a small dish with saturated salt solution in the bottom of the metal 
container, place the seeded plates on a stand over the salt solu tion and close the lid of the container. Incubate 
at 37 °C ± 1 °C. Examine the SMS plates after one week for the development of pink or red colonies. If no  
16 © UNBS  2010  – All rights reserved  
 colonies have developed, incubate for a further two weeks. Examine the plates for the presence of pi nk or red 
colonies, indicating the presence of red halophylic bacteria, and check for compliance with clause 7.   
© UNBS 2010  – All rights reserved  17 
 Bibliography  
[1] CODEX STAN 150 -1985 , Codex Standard for food grade salt  
[2] EAS 35, Harmonised East African Standard for Edible Salts  
[3] MS 47 :1986 , Specification for refined edible salt,  published by Mauritius Standards Bureau  
[4] Draft Food and Drugs ( Salt iodisation)  Regulations, 2010  
[5] TZS 132: 1988, Specification for edible common salt, published by t he Tanzania Bureau of Standards   
18 © UNBS  2010  – All rights reserved  
 Certif ication marking  
Products that conform to Uganda standards may be marked with Uganda National Bureau of Standards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is governed by the Standards Act, and the Regulati ons made 
thereunder. This mark can be used only by those licensed under the certification mark scheme operated by 
the Uganda National Bureau of Standards and in conjunction with the relevant Uganda Standard. The 
presence of this mark on a product or in rel ation to a product is an assurance that the goods comply with the 
requirements of that standard under a system of supervision, control and testing in accordance with the 
certification mark scheme of the Uganda National Bureau of Standards. UNBS marked prod ucts are 
continually checked by UNBS for conformity to that standard.  
Further particulars of the terms and conditions of licensing may be obtained from the Director, Uganda 
National Bureau of Standards.  
  
© UNBS 2010  – All rights reserved  19 
 Food Fortification Logo  
Products that conform to  Uganda Standards for fortified food products may be marked National food 
fortification logo shown in the figure below.  
The use of the food fortification logo is governed by the Food Fortification Regulations. Further particulars of 
the terms and conditio ns of use of the logo may be obtained from Uganda National Bureau of Standards.  
 
 DUS 203:2010    
 
ICS 71.060.50  
Price based on 24 page s 
© UNBS 2010 – All rights reserved